Identification of cancer stem cells in a Tax-transgenic (Tax-Tg) mouse model of adult T-cell leukemia/lymphoma by Jumpei Yamazaki, Takuo Mizukami, Kazuya Takizawa, Madoka Kuramitsu, Haruka Momose, Atsuko Masumi, Yasushi Ami, Hideki Hasegawa, William W. Hall, Hajime Tsujimoto, Isao Hamaguchi, and Kazunari Yamaguchi Blood Volume 114(13):2709-2720 September 24, 2009 ©2009 by American Society of Hematology

Transplantation of Tax-Tg mouse-derived splenic mononuclear cells to NOD/SCID mice. Transplantation of Tax-Tg mouse-derived splenic mononuclear cells to NOD/SCID mice. (A) Experimental design of the transplantation assay. (B) Remarkable splenomegaly was observed in the lymphoma-reconstituted NOD/SCID mouse. Spl indicates spleen; and Liv, liver. The dotted line shows the outline of the enlarged spleen. (C) Cytospin analysis of spleen cells isolated from reconstituted lymphoma in the NOD/SCID mouse. The spleen was filled with ATL-like lymphomatous cells. (D) Surface marker analysis of lymphomatous cells from spleen. These had the identical phenotype of lymphomatous cell reconstituted by Tax-Tg–derived splenic mononuclear cells: CD2−, CD4−, CD8−, cytoplasmic CD3+, and surface CD25+ and CD44+. (E) Schematic representation of the PCR assay to identify and confirm the Tax transgenic integration site. Lck-Tax transgenes were tandemly inserted on the chromosome 4 (Chr.4) in the original transgenic animals. (F) Genotyping of mononuclear cells in the spleen and BM. WT PCR product (300 bp) was detected in both the normal and CSC-transplanted NOD/SCID spleen and BM. However, Tax-Tg (TG) PCR products identifying the expected integration site of the transgene (200 bp) were detected only in the reconstituted ATL-like lymphomatous cells in spleen and BM. TP+ indicates transplantation. Jumpei Yamazaki et al. Blood 2009;114:2709-2720 ©2009 by American Society of Hematology

Flow cytometric analysis of NOD/SCID repopulating ATL-like lymphoma cells. Flow cytometric analysis of NOD/SCID repopulating ATL-like lymphoma cells. Lymphoma and leukemia were generated in NOD/SCID mice by the transplantation of frozen stocked 4th-passage Tax-Tg SLCs. SLCs were isolated from spleen. (A) Histograms of isotype APC, PE, and FITC markers as controls. Expression profiles were divided into 4 patterns: partial and low, heterogeneous, and major types. (B) Partial and low expression: CD127, CD117, CD123, FoxP3, CD133, CD90, and CD34 are expressed at low levels in SLCs. (C) Heterogeneous expression: CD71 and CD25 are heterogeneously expressed in SLCs. (D) Major: CD38, CD24, and Sca-1 are highly expressed in SLCs. The percentage of individual subpopulations was determined according to isotype control in each assay. Dead cells were gated out by propidium iodide. (E) Triple-staining analysis with CD38, CD71, and CD117 or CD133 in the SLCs. CD38−/CD71−/CD117+ cells were 0.03% and CD38−/CD71−/CD133+ cells were 0% of total SLCs. Jumpei Yamazaki et al. Blood 2009;114:2709-2720 ©2009 by American Society of Hematology

Functional analysis in the NOD/SCID repopulating ATL-like lymphoma cells. Functional analysis in the NOD/SCID repopulating ATL-like lymphoma cells. (A) SP cell analysis in the NOD/SCID repopulating ATL-like lymphoma cells. The SP regions are indicated by a trapezoid on each panel. (Left panel) Approximately 0.064% of SP cells were observed in the SLCs. (Right panel) SP cell analysis after treatment with verapamil (100 μM), where the SP fraction was lost. (B) Triple-staining analysis of CD38, CD71, and CD117 in the SP fraction. More than 50% of CD38−/CD71−/CD117+ corresponded to the SP fraction. (C) FACS CD38−/CD71−/CD117+ and CD38−/CD71−/CD117− cells. (D) Cytospin analysis of the CSC candidate (CD38−/CD71−/CD117+) and (E) non-CSC candidate (CD38+/CD71+/CD117−) populations. Jumpei Yamazaki et al. Blood 2009;114:2709-2720 ©2009 by American Society of Hematology

Regenerative potential of ATL-like lymphoma in 102 CSCs Regenerative potential of ATL-like lymphoma in 102 CSCs. ATL-like lymphoma-regenerative activity was assessed by the transplantation of 102 CSCs, the non-CSC fraction, and SLCs. (A) ATL-like lymphoma was regenerated by the transplantation of 102 CSCs into t... Regenerative potential of ATL-like lymphoma in 102 CSCs. ATL-like lymphoma-regenerative activity was assessed by the transplantation of 102 CSCs, the non-CSC fraction, and SLCs. (A) ATL-like lymphoma was regenerated by the transplantation of 102 CSCs into the NOD/SCID mouse at 60 days. (B) Marked splenomegaly was observed in the NOD/SCID recipient mice. (C) Ascites was also observed in the NOD/SCID recipient mice. (D) Total spleen weight was significantly increased only in the CSC-transplanted NOD/SCID mouse. (E) SP analysis of ATL-like lymphoma cells generated by the transplantation of 102 CSCs. (Left panel) The SP fraction (total = 0.066%) was present after CSC transplantation. (Right panel) The SP fraction was lost in the dot plot with treatment by 100 μM verapamil. (F) Surface marker analysis in the lymphoma cells regenerated by the 102 CSC transplantation. The CSC candidate cells (CD38−/CD71−/CD117+) were also regenerated after transplantation of 102 CSCs. Jumpei Yamazaki et al. Blood 2009;114:2709-2720 ©2009 by American Society of Hematology

Histologic and immunohistochemical analyses of spleen after transplantation. Histologic and immunohistochemical analyses of spleen after transplantation. At 60 days, lymphoma was regenerated after the transplantation of 105 SLCs and 102 CSCs. No lymphoma was observed after the transplantation of 102 non-CSCs. (A) PAS-hematoxylin staining in the 105 SLCs recipient spleen. (Top panel) Low magnification. (Bottom panel) High magnification. Strong PAS+-stained cells were observed (). (B) PAS-hematoxylin staining in the 1 × 102 CSCs recipient spleen. (C) PAS-hematoxylin staining in the 1 × 102 non-CSCs recipient spleen. No strong PAS+ staining cells were evident. (D-I) Immunohistochemistry of CD44 and CD117, shown in the 105 SLC recipient spleen (D,G), in the 102 CSC recipient spleen (E,H), and in the 1 × 102 SLC recipient spleen (F,I). CD44 and CD117 expression is detected in the lymphoma in the spleen after 1 × 105 SLC and 1 × 102 CSC transplantation. (J) Hematoxylin and eosin (H&E) staining of the normal NOD/SCID mouse BM. Various types of blood cells, including megakaryocytes and erythroid cells, were evident. (K) Hematoxylin and eosin staining of lymphoma reconstituted in the NOD/SCID mouse BM. The BM tissue was uniformly filled with ATL-like lymphomatous cells. (L) Infiltration of lymphomatous cells was also observed in the liver. (M) Infiltration of lymphomatous cells in lung. (N) Infiltration of lymphomatous cells in lymph nodes. (O) Infiltration of lymphomatous cells was not observed in the epidermal tissues. *Lymphomatous cells. (Closed scale bar, 50 μm; open scale bar, 20 μm.)‏ Jumpei Yamazaki et al. Blood 2009;114:2709-2720 ©2009 by American Society of Hematology

Flow cytometric analysis of lymphomatous cells in the NOD/SCID BM Flow cytometric analysis of lymphomatous cells in the NOD/SCID BM. NOD/SCID repopulating lymphomatous cells were isolated from BM. (A) Triple staining analysis with CD38, CD71, and CD117 in the BM SLCs. As was observed in spleen, the CSC candidates were als... Flow cytometric analysis of lymphomatous cells in the NOD/SCID BM. NOD/SCID repopulating lymphomatous cells were isolated from BM. (A) Triple staining analysis with CD38, CD71, and CD117 in the BM SLCs. As was observed in spleen, the CSC candidates were also observed in the BM. (B) Histologic analysis of ATL-like lymphomatous cells in the NOD/SCID BM. In the normal NOD/SCID BM, CD3+ cells were a rare population (). (C) In the reconstituted NOD/SCID mouse BM, CD3+ cells were readily identified (arrow). (D) CD117+ cells as a surrogate CSC marker could be detected in the osteoblastic niche of the trabecular bone (arrow). (E) In the medullary region, CD117+ cells (CSCs) were also detected in the vascular niche (). T.b. indicates endosteal region in the trabecular bone; V, vascular zone; TP+, transplantation; and NT, no transplantation. Scale bar represents 20 μm. Jumpei Yamazaki et al. Blood 2009;114:2709-2720 ©2009 by American Society of Hematology

Molecular characterization of the CSCs and non-CSC fraction. Molecular characterization of the CSCs and non-CSC fraction. FACS-sorted 5000 CSCs and non-CSCs were used to purify RNA and synthesize cDNA. Gene expression level was determined relative to β-actin. (A) CD117 expression was used to evaluate the efficacy of cell sorting. (Top panel) CD117 expression was higher in the CSCs than in the non-CSCs. (Bottom panel) Tax gene expression was not detected in CSCs. (B) Notch1 and Bmi1 expression was down-regulated in CSCs. CD44 expression was up-regulated in CSCs. No difference was observed in the expression of the other genes, Rex1, Flt3, SCL/tal-1, N-cadherin, Oct-4, and Nanog in the CSCs and non-CSC fraction. *P < .05 (significant). Jumpei Yamazaki et al. Blood 2009;114:2709-2720 ©2009 by American Society of Hematology